Compared to other racial/ethnic groups in the US, Black men who have sex with men (MSM), once diagnosed, are less likely to be optimally engaged in HIV care and treatment. This undermines the promise of recent prevention approaches for reducing the disproportionate effects of HIV/AIDS on Black communities, emphasizing the urgency for increased research focus and intervention development. Understanding HIV care engagement in the context of the dyad may be part of a comprehensive effort to addressing multilevel influences on HIV care engagement outcomes that are unique to HIV+ Black MSM towards achieving the maximum public health benefit of treatment-as-prevention. However, the scarcity of dyad-level research limits our understanding of couple dynamics involved in HIV care engagement to inform intervention development targeting the couple, underscoring the need for couple-based studies of relational dynamics important to the HIV care engagement of the HIV+ partner(s). Mobile technology-based strategies (mHealth) offer tremendous potential as an acceptable, feasible, and effective intervention platform for enhancing HIV care engagement among HIV+ Black MSM in couples by facilitating couple dynamics optimal to HIV care engagement. Further, mHealth offers potential in addressing limitations in previous intervention research with couples, one of which is the dissipation of intervention effects over time due to absence of booster sessions. Therefore, the aims of the study are to: elucidate the effects of couple dynamics on HIV care engagement among partnered synthesize the quantitative and qualitative (mixed methods) outcomes from Aim 1 to identify the issues the intervention will target, and to iteratively determine core components of a couple-based intervention for HIV+ Black MSM (Aim 2); and develop a novel, technology-based intervention prototype for enhancing HIV care engagement among HIV+ Black MSM in couples (Aim 3). HIV+ Black MSM (Aim 1); The overall objective of this application is to achieve a better understanding of the couple dynamics involved in HIV care engagement among HIV+ Black men in same-sex relationships. The end goal is the development of an mHealth tool that targets couple dynamics important to enhancing HIV care engagement. Through these aims, I will acquire additional training necessary for my career development in (a) theory and mixed methods for conducting couple-based research, (b) formative research in intervention development, and (c) prototype design. These research and career development activities will build the foundation to my becoming an independent, NIH-funded investigator with skills to conduct couple-based intervention research that is part of a comprehensive effort in HIV prevention integrating advances in technology and behavioral medicine to reduce racial/ethnic disparities in HIV.